Honda Insight Forum banner

1 - 20 of 22 Posts

·
Registered
Joined
·
140 Posts
Discussion Starter #1
I purchased my 2001 MT Insight a year ago at 104k miles and in the last 6 months I have noticed my MPG drop to just under 50 with 90% city driving and only about 55-60 on the Freeway.

Having implemented all the basic hypermiling techniques (tire pressure, pedal usage, coasting, etc) with very little gains I started looking at maintenance solutions. I changed the oil, installed OEM Bridgestone RE92 tires, and checked the brakes.

Just today I received the OEM spark plugs from hondapartsnow.com (14.62ea+S/H) and I just finished throwing them in and what happened? 77.5MPG trip mileage happened. Honda recommends plugs get changed at 105k and I was at 119k so they were due, I just didn't realize they made that much of a difference.

SO, if you are over 105k and the plugs haven't been done, I highly recommend it. Here are the basics:

- Our engines are finely tuned and they require indexed plugs. Basically what this means is that there is a stamp next to each cylinder which will be either lettered A, B, C or D. Each engine is different so you need to order the right part numbers.
- Get a torque wrench that will do in-lb and set it to 204in-lb (17ft-lb). It is of the upmost importance that you get this right because it will affect mileage and how well the car runs. Not to mention you can mess up the threads.

- The plugs are pre-gapped to 1.0 - 1.1mm (mine were 1.1mm). My old plugs were gapped at 1.175mm, 1.15mm and 1.175mm respectively so it makes a difference.
 

·
Registered
Joined
·
143 Posts
Interesting. I recently got my plugs done, hadn't noticed a change in the mileage. Though, it hadn't decreased prior to the replacement.
 

·
Registered
Joined
·
33 Posts
I checked rockauto.com for my 2001 insight and the spark plugs are 4-6 bucks a piece. WHy are they so much cheaper? Will they work?
 

·
Registered
Joined
·
140 Posts
Discussion Starter #5
I suspect that the advertising on this website is purely generated by a network of forums and it looks for key words, not specific models.

The plugs for sale at rockauto.com are generic plugs and since I've never heard of indexed plugs for any other vehicle I doubt that manufacturers think there is that much of a difference. The truth is that with our vehicles there is a difference. I read a post with an Aussie who had a fouled plug and it was one of these generic plugs that a mechanic had thrown in because they didn't know the difference.

Are they different? Yes. Should you get the cheaper ones anyway? I wouldn't recommend it. It's kind of like putting a 13" tire on a car with 14" tires... it will probably work so-so at best but eventually there will be trouble.
 

·
Registered
Joined
·
33 Posts
ARe you sure these are the oem plugs?
I checked the website, but when I went to the honda dealer today they want $40 for each spark plug!
Sheesh!
 

·
Registered
Joined
·
140 Posts
Discussion Starter #7

·
Registered
Joined
·
140 Posts
Discussion Starter #9
learned it the hard way, i had this preconcieved notion before that generic plugs are applicable to all, so i bought an aftermarket one, AC Delco Spark Plug Wire, without checking my engine first. result, flushed down 30+bucks.
Yeah, if it were just about any other car you would have been right but because these insights are so finely tuned for mileage, even which direction the spark plug head faces matters.
 

·
Registered
Joined
·
673 Posts
Changed mine around 110k and noticed nothing. Feels like wasted cash to me. Wish I had a noticeable jump, but oh well...
 

·
Registered
Joined
·
140 Posts
Discussion Starter #11
Changed mine around 110k and noticed nothing. Feels like wasted cash to me. Wish I had a noticeable jump, but oh well...
Diminishing returns my friend. If you're getting the kind of mileage you list in your signature then new plugs aren't going to help that much.
 

·
Registered
Joined
·
40 Posts
43mpg? Ick

Hi:

I just inherited my dad's 2000 Insight (170k miles, had the pack replaced at 110k) because he went and got a volt. And although I also have an electric car (94 Geo Prizm, 50kw Dolphin system) I kind of like the Insight for longer trips.

Anyway, he noticed that the MPG in the last few years dropped from 70 to around 40. I've been getting 42 on it, which felt odd as I know how to stretch mileage with the Prizm.

Pulled the plugs, all 3 are type B and match the cyl. However the gap on plug #2 was only .025 while 1 was .045 and 3 was .037. I re-gapped 2 and 3 to about .045 or so and re-installed the plugs with my old bar torque wrench which has a nice line between 15 and 20 ft lb.

Question: Can a tight gap cause that much performance drop? Also how critical is the 17ft lb? Will a bar type torque wrench give an accurate enough reading?
 

·
Moderator
Joined
·
6,916 Posts
It will probably help, but there's something else wrong with that kind of MPG hit.

Any codes? Dunno, kinda shooting blind. Are the tires aired up? Fresh air filter? Any herky jerky? The EGR plate may need to be cleaned.
 

·
Registered
Joined
·
40 Posts
No, no codes. However when I blew it and forgot to hook up one of the spark plug coils the engine light came on *immediately*. Then went off just as fast, guess it's a transient error.

The Maint light is on, but I can't turn it off because the trip button is defective (I'll have to figure that out another day. Whole car probably has to come apart I'm guessing).

Is there a doc for cleaning the EGR plate? Would that cause a code in normal operation?

Chris
 

·
Registered
Joined
·
265 Posts
Just to add another data point to the spark plug discussion. I recently squired a 2001 Insight CVT with around 194k miles. One of the first things I did was give it a quick tune up, including new plugs.

I used generic iridium plugs and they seem to be working fine. For my commute I can still get high 50's without drafting and in hilly San Diego. Maybe I got lucky and they indexed themselves with my seat of the pants torque wrench.

Well I don't doubt that there is an advantage to indexed plugs, it seems like there have been some slight improvements in spark plug technology over the past 10 years. I've even seen plugs with FOUR of the prongs, at that point indexing really doesn't matter.
 

·
Moderator
Joined
·
6,916 Posts
The point of indexing the plugs is to make sure the ground electrode isn't shielding the mixture from the spark.

In our cars, when indexed the open end of the electrode faces towards the non-VTEC intake valve.
 

·
Registered
Joined
·
109 Posts
I replaced mine at just over 100K as recommended with the Honda parts and it was a waste, the old ones were clean, square and as perfect as the new ones. Maybe I'll swap the originals back in at 300 or 400k to get my money's worth.

I suspect something else is wrong and that's what chewed your plugs up. I'm also sure gap is important.
 

·
Registered
Joined
·
40 Posts
Still 43mpg

Well, it's been a month since I re-gapped the plugs and I went through a tank of gas. 440 miles, 43mpg. Yuck.

What would be the symptom of a clogged EGR system? Still no codes in the computer, the maint light is on because the trip button on the dash is broken. Is there another way to get it off? Could that be causing it?

Tried 93 octane gas, still eh. One thing I have noticed is when I'm on the highway and I feather the throttle it doesn't stay at 75mpg, drops to 50. Also the battery is going dead then charging then normal, then it just drops to dead again. But no IMA light and it still seems to work.

C
 

·
Moderator
Joined
·
6,916 Posts
Clogged EGR will give herky-jerky when it gets bad enough.

Sounds like your battery issues are keeping your MPG down. My suggestion is to be more aware of using assist, and not use it so much. This means keeping the engine RPMs up a little as you accelerate, ahd while this will lower your fuel economy, it won't lower it as much as having to constantly charge the battery back up.
 

·
Registered
Joined
·
38 Posts
The plugs here: Genuine Honda Ignition Coil - 2001 Honda Insight Ignition Coil - Hatchback DX A/C 5MT KA E__05 are OEM. You need to look at the marking on your engine to determine to order the A, B, C or D plugs because each cylinder on each engine is different. My dealer wanted $24 each, and the hondapartsnow price is down to $14.10 each.

DO NOT order these without checking which ones you need.
Hey everybody, sorry to bump a thread so old but I have been searching on HOW to check which plugs I need to buy, but haven't found any info on that yet. Can anyone help or should I just resort to visiting and asking the dealer on my way home from work in the morning?
 
1 - 20 of 22 Posts
About this Discussion
21 Replies
11 Participants
MosquitoXR13
Honda Insight Forum
We’re the ultimate Honda Insight forum to talk about Honda’s hybrid car and its fuel economy and specs!
Full Forum Listing
Top